Vehicles, especially large cargo-carrying vehicles, such as tractor-trailers and buses, operate in a variety of load conditions, ranging from fully loaded, to empty. The horsepower required for moving the vehicle will vary depending on the load conditions. The way a driver operates a vehicle can also impact the fuel economy. For example, by gradually transitioning from a stopped state to a cruising speed, less fuel may be consumed than by rapidly accelerating from a stopped state. However, many drivers feel the pressure of time constraints, and the desire to minimize time spent on a delivery route will often outweigh the desire to maximize fuel economy.
Due to increasing cost of fuel, it is therefore desirable to provide a system that maximizes fuel economy, with minimal dependence on the driving techniques or actions of the vehicle operator. It is also desirable to provide such a system that can interface with an existing electronic engine control module (ECM). Electronic control modules for managing the operation of internal combustion engines are well known and widely used in the automotive and tractor truck industries. Such modules are typically operable to control engine fueling as well as many other engine and/or vehicle operating conditions.
To the extent not inconsistent with the present disclosure, U.S. Pat. Nos. 5,477,827; 5,937,826; 6,135,918; and 6,412,789 are incorporated herein by reference.